Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates generally to composite molded articles and the process of making the composite molded articles and more specifically to a method for applying pressure to the mold during the curing process.
2. Description of the Related Art
Those concerned with these and other problems recognize the need for an improved Method of Making a Cold Cured Composite Molded Article.
The use of polyurethane adhesives or binders for binding particulate materials is well know. The materials are thoroughly mixed until the polyurethane has fully integrated with the particulate material. The mixture is then compacted in a mold or press to the desired density and cured using heat, moisture, usually in the form of steam, and time. Pressure is required to maintain the shape and density of the article while heat is used to reduce the cure times. For all practical purposes, the use of heat is required during many curing processes.
In the situation where heat is utilized, typically the material will be pressed and heated by the same apparatus. The molds for this press must be able to withstand the heat repeatedly applied and can therefore be expensive to produce and alter. Additionally, the apparatus maintains the pressure until the heat curing is complete. The article is then removed from the press and the process starts again.
In the situations where heat is not utilized, i.e. a cold curing, the material is placed in a mold. Pressure must then be applied to the mold until the curing is complete. An apparatus such as is used in the heat curing systems can be utilized to provide the pressure without heat but is excessive in terms of what is actually needed.
Thus, there is a need to overcome the aforementioned drawbacks and a need for an improved method of making a cold cured composite article.
The present invention relates generally to composite molded articles and the process of making the composite molded articles and more specifically to a method for applying pressure to the mold during a cold curing process.
The present invention utilizes molds which require pressure in only one direction or dimension during the cold curing process. The mold is filled with the composite material, and inserted between two series of rollers. The rollers are positioned at an appropriate distance such that the proper amount of pressure is applied to the mold in the requisite direction or dimension.
At least some of the rollers are motorized such that the mold is propelled, though typically not at a great speed, through the two series of rollers. The cure time is controlled by controlling how fast the mold is propelled through the rollers.
Therefore, an object of the present invention is the provision of an improved Method of Making a Cold Cured Composite Molded Article.
Another object is to provide a Method of Making a Cold Cured Composite Molded Article utilizing molds requiring pressure in only one direction or dimension.
A further object is to provide a Method of Making a Cold Cured Composite Molded Article which is economical and efficient.